If your friend got CSE at IIT Bombay, that means he/she must belong to the reserved category. Reservation is good (not caste-based) as it evens out the playing field for the students belonging to this category.
For instance, this friend of yours has a rank of 10k- if he is a reservation candidate, his rank would depend entirely on his category. This arrangement is separate from the normal ranking system. And as you've mentioned, if your friend has secured a rank of 10k, chances are- he might have belonged to a list that's open extended. These students from the open extended list don't save a seat for themselves in IITB CSE. But if he has still managed to grab a seat at IITB CSE too, his AIR must have been >25. Comparing such a candidate's rank to the general category list, it should be around 3-4k.
This incident may not reflect equality, but assuming it was a genuine case, it is justified.